uart-bridge: expose both HW UARTs

With these changes, both HW UARTs will be exposed as two independent USB-UART
bridge controllers.

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>

CMakeLists.txt

@@ -11,8 +11,8 @@ pico_sdk_init()
 add_executable(uart_bridge uart-bridge.c usb-descriptors.c)
 
 target_include_directories(uart_bridge PUBLIC
-	pico-sdk/lib/tinyusb/src
+	./
-	pico-sdk/src/rp2_common/pico_stdio_usb/include)
+	pico-sdk/lib/tinyusb/src)
 
 target_link_libraries(uart_bridge
 	pico_multicore

tusb_config.h

@@ -0,0 +1,36 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2020 Raspberry Pi (Trading) Ltd.
+ * Copyright (c) 2020 Damien P. George
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ */
+
+#ifndef _PICO_STDIO_USB_TUSB_CONFIG_H
+#define _PICO_STDIO_USB_TUSB_CONFIG_H
+
+#define CFG_TUSB_RHPORT0_MODE   (OPT_MODE_DEVICE)
+
+#define CFG_TUD_CDC             (2)
+#define CFG_TUD_CDC_RX_BUFSIZE  (256)
+#define CFG_TUD_CDC_TX_BUFSIZE  (256)
+
+#endif

uart-bridge.c

@@ -7,10 +7,8 @@
 #include <hardware/structs/sio.h>
 #include <hardware/uart.h>
 #include <pico/multicore.h>
-#include <pico/stdio_usb.h>
 #include <pico/stdlib.h>
 #include <tusb.h>
-#include <string.h>
 
 #if !defined(MIN)
 #define MIN(a, b) ((a > b) ? b : a)
@@ -18,10 +16,6 @@
 
 #define LED_PIN 25
 
-#define UART_ID uart0
-#define UART_TX_PIN 0
-#define UART_RX_PIN 1
-
 #define BUFFER_SIZE 64
 
 #define DEF_BIT_RATE 115200
@@ -29,20 +23,36 @@
 #define DEF_PARITY 0
 #define DEF_DATA_BITS 8
 
-static cdc_line_coding_t CDC_LC = {
+typedef struct {
-	.bit_rate = DEF_BIT_RATE,
+	uart_inst_t *const inst;
-	.stop_bits = DEF_STOP_BITS,
+	uint8_t tx_pin;
-	.parity = DEF_PARITY,
+	uint8_t rx_pin;
-	.data_bits = DEF_DATA_BITS,
+} uart_id_t;
+
+typedef struct {
+	cdc_line_coding_t usb_lc;
+	cdc_line_coding_t uart_lc;
+	uint8_t uart_buffer[BUFFER_SIZE];
+	uint32_t uart_pos;
+	mutex_t uart_mtx;
+	uint8_t usb_buffer[BUFFER_SIZE];
+	uint32_t usb_pos;
+	mutex_t usb_mtx;
+} uart_data_t;
+
+const uart_id_t UART_ID[CFG_TUD_CDC] = {
+	{
+		.inst = uart0,
+		.tx_pin = 0,
+		.rx_pin = 1,
+	}, {
+		.inst = uart1,
+		.tx_pin = 4,
+		.rx_pin = 5,
+	}
 };
 
-static uint8_t UART_BUFFER[BUFFER_SIZE];
+uart_data_t UART_DATA[CFG_TUD_CDC];
-static uint32_t UART_POS = 0;
-static mutex_t UART_MTX;
-
-static uint8_t USB_BUFFER[BUFFER_SIZE];
-static uint32_t USB_POS = 0;
-static mutex_t USB_MTX;
 
 static inline uint databits_usb2uart(uint8_t data_bits)
 {
@@ -80,133 +90,186 @@ static inline uint stopbits_usb2uart(uint8_t stop_bits)
 	}
 }
 
-int update_uart_cfg(void)
+void update_uart_cfg(uint8_t itf)
 {
-	static cdc_line_coding_t last_cdc_lc = {
+	const uart_id_t *ui = &UART_ID[itf];
-		.bit_rate = DEF_STOP_BITS,
+	uart_data_t *ud = &UART_DATA[itf];
-		.stop_bits = DEF_STOP_BITS,
-		.parity = DEF_PARITY,
-		.data_bits = DEF_DATA_BITS,
-	};
-	int updated = 0;
 
-	if (last_cdc_lc.bit_rate != CDC_LC.bit_rate) {
+	if (ud->usb_lc.bit_rate != ud->uart_lc.bit_rate) {
-		uart_set_baudrate(UART_ID, CDC_LC.bit_rate);
+		uart_set_baudrate(ui->inst, ud->usb_lc.bit_rate);
-		updated = 1;
+		ud->uart_lc.bit_rate = ud->usb_lc.bit_rate;
 	}
 
-	if ((last_cdc_lc.stop_bits != CDC_LC.stop_bits) ||
+	if ((ud->usb_lc.stop_bits != ud->uart_lc.stop_bits) ||
-	    (last_cdc_lc.parity != CDC_LC.parity) ||
+	    (ud->usb_lc.parity != ud->uart_lc.parity) ||
-	    (last_cdc_lc.data_bits != CDC_LC.data_bits)) {
+	    (ud->usb_lc.data_bits != ud->uart_lc.data_bits)) {
-		uart_set_format(UART_ID, databits_usb2uart(CDC_LC.data_bits),
+		uart_set_format(ui->inst,
-				stopbits_usb2uart(CDC_LC.stop_bits),
+				databits_usb2uart(ud->usb_lc.data_bits),
-				parity_usb2uart(CDC_LC.parity));
+				stopbits_usb2uart(ud->usb_lc.stop_bits),
-		updated = 1;
+				parity_usb2uart(ud->usb_lc.parity));
+		ud->uart_lc.data_bits = ud->usb_lc.data_bits;
+		ud->uart_lc.parity = ud->usb_lc.parity;
+		ud->uart_lc.stop_bits = ud->usb_lc.stop_bits;
 	}
-
-	if (updated)
-		memcpy(&last_cdc_lc, &CDC_LC, sizeof(cdc_line_coding_t));
-
-	return updated;
 }
 
-void usb_cdc_process(void)
+void usb_read_bytes(uint8_t itf) {
-{
+	uint32_t len = tud_cdc_n_available(itf);
-	uint32_t count;
-	uint32_t len;
 
-	tud_cdc_get_line_coding(&CDC_LC);
+	if (len) {
+		uart_data_t *ud = &UART_DATA[itf];
 
-	/* Read bytes from USB */
+		mutex_enter_blocking(&ud->usb_mtx);
-	if (tud_cdc_available()) {
-		mutex_enter_blocking(&USB_MTX);
 
-		len = MIN(tud_cdc_available(), BUFFER_SIZE - USB_POS);
+		len = MIN(len, BUFFER_SIZE - ud->usb_pos);
 		if (len) {
-			count = tud_cdc_read(USB_BUFFER, len);
+			uint32_t count;
-			USB_POS += count;
+
+			count = tud_cdc_n_read(itf, ud->usb_buffer, len);
+			ud->usb_pos += count;
 		}
 
-		mutex_exit(&USB_MTX);
+		mutex_exit(&ud->usb_mtx);
 	}
+}
 
-	/* Write bytes to USB */
+void usb_write_bytes(uint8_t itf) {
-	if (UART_POS) {
+	uart_data_t *ud = &UART_DATA[itf];
-		mutex_enter_blocking(&UART_MTX);
 
-		count = tud_cdc_write(UART_BUFFER, UART_POS);
+	if (ud->uart_pos) {
+		uint32_t count;
+
+		mutex_enter_blocking(&ud->uart_mtx);
+
+		count = tud_cdc_n_write(itf, ud->uart_buffer, ud->uart_pos);
 		if (count) {
-			UART_POS -= count;
+			ud->uart_pos -= count;
-			tud_cdc_write_flush();
+			tud_cdc_n_write_flush(itf);
 		}
 
-		mutex_exit(&UART_MTX);
+		mutex_exit(&ud->uart_mtx);
 	}
 }
 
+void usb_cdc_process(uint8_t itf)
+{
+	uart_data_t *ud = &UART_DATA[itf];
+	int con = tud_cdc_n_connected(itf);
+
+	tud_cdc_n_get_line_coding(itf, &ud->usb_lc);
+	usb_read_bytes(itf);
+	usb_write_bytes(itf);
+}
+
 void core1_entry(void)
 {
 	tusb_init();
 
 	while (1) {
-		tud_task();
+		int itf;
+		int con = 0;
 
-		if (tud_cdc_connected()) {
+		tud_task();
-			usb_cdc_process();
+	
-			gpio_put(LED_PIN, 1);
+		for (itf = 0; itf < CFG_TUD_CDC; itf++) {
-		} else {
+			if (tud_cdc_n_connected(itf)) {
-			gpio_put(LED_PIN, 0);
+				con = 1;
+				usb_cdc_process(itf);
+			}
 		}
+
+		gpio_put(LED_PIN, con);
 	}
 }
 
+void uart_read_bytes(uint8_t itf) {
+	const uart_id_t *ui = &UART_ID[itf];
+
+	if (uart_is_readable(ui->inst)) {
+		uart_data_t *ud = &UART_DATA[itf];
+
+		mutex_enter_blocking(&ud->uart_mtx);
+
+		while (uart_is_readable(ui->inst) &&
+			ud->uart_pos < BUFFER_SIZE) {
+			ud->uart_buffer[ud->uart_pos] = uart_getc(ui->inst);
+			ud->uart_pos++;
+		}
+
+		mutex_exit(&ud->uart_mtx);
+	}
+}
+
+void uart_write_bytes(uint8_t itf) {
+	uart_data_t *ud = &UART_DATA[itf];
+
+	if (ud->usb_pos) {
+		const uart_id_t *ui = &UART_ID[itf];
+
+		mutex_enter_blocking(&ud->usb_mtx);
+
+		uart_write_blocking(ui->inst, ud->usb_buffer, ud->usb_pos);
+		ud->usb_pos = 0;
+
+		mutex_exit(&ud->usb_mtx);
+	}
+}
+
+void init_uart_data(uint8_t itf) {
+	const uart_id_t *ui = &UART_ID[itf];
+	uart_data_t *ud = &UART_DATA[itf];
+
+	/* Pinmux */
+	gpio_set_function(ui->tx_pin, GPIO_FUNC_UART);
+	gpio_set_function(ui->rx_pin, GPIO_FUNC_UART);
+
+	/* USB CDC LC */
+	ud->usb_lc.bit_rate = DEF_BIT_RATE;
+	ud->usb_lc.data_bits = DEF_DATA_BITS;
+	ud->usb_lc.parity = DEF_PARITY;
+	ud->usb_lc.stop_bits = DEF_STOP_BITS;
+
+	/* UART LC */
+	ud->uart_lc.bit_rate = DEF_BIT_RATE;
+	ud->uart_lc.data_bits = DEF_DATA_BITS;
+	ud->uart_lc.parity = DEF_PARITY;
+	ud->uart_lc.stop_bits = DEF_STOP_BITS;
+
+	/* Buffer */
+	ud->uart_pos = 0;
+	ud->usb_pos = 0;
+
+	/* Mutex */
+	mutex_init(&ud->uart_mtx);
+	mutex_init(&ud->usb_mtx);
+
+	/* UART start */
+	uart_init(ui->inst, ud->usb_lc.bit_rate);
+	uart_set_hw_flow(ui->inst, false, false);
+	uart_set_format(ui->inst, databits_usb2uart(ud->usb_lc.data_bits),
+			stopbits_usb2uart(ud->usb_lc.stop_bits),
+			parity_usb2uart(ud->usb_lc.parity));
+}
+
 int main(void)
 {
 	uint8_t ch;
 	int rc;
+	int itf;
 
-	mutex_init(&UART_MTX);
+	for (itf = 0; itf < CFG_TUD_CDC; itf++)
-	mutex_init(&USB_MTX);
+		init_uart_data(itf);
 
 	gpio_init(LED_PIN);
 	gpio_set_dir(LED_PIN, GPIO_OUT);
 
-	uart_init(UART_ID, CDC_LC.bit_rate);
-
-	gpio_set_function(UART_TX_PIN, GPIO_FUNC_UART);
-	gpio_set_function(UART_RX_PIN, GPIO_FUNC_UART);
-
-	uart_set_hw_flow(UART_ID, false, false);
-	uart_set_format(UART_ID, databits_usb2uart(CDC_LC.data_bits),
-			stopbits_usb2uart(CDC_LC.stop_bits),
-			parity_usb2uart(CDC_LC.parity));
-
 	multicore_launch_core1(core1_entry);
 
 	while (1) {
-		update_uart_cfg();
+		for (itf = 0; itf < CFG_TUD_CDC; itf++) {
-
+			update_uart_cfg(itf);
-		/* Read bytes from UART */
+			uart_read_bytes(itf);
-		if (uart_is_readable(UART_ID)) {
+			uart_write_bytes(itf);
-			mutex_enter_blocking(&UART_MTX);
-
-			while (uart_is_readable(UART_ID) &&
-			       UART_POS < BUFFER_SIZE) {
-				UART_BUFFER[UART_POS] = uart_getc(UART_ID);
-				UART_POS++;
-			}
-
-			mutex_exit(&UART_MTX);
-		}
-
-		/* Write bytes to UART */
-		if (USB_POS) {
-			mutex_enter_blocking(&USB_MTX);
-
-			uart_write_blocking(UART_ID, USB_BUFFER, USB_POS);
-			USB_POS = 0;
-
-			mutex_exit(&USB_MTX);
 		}
 	}
 

usb-descriptors.c

@@ -31,9 +31,18 @@
 #define USBD_VID (0x2E8A) // Raspberry Pi
 #define USBD_PID (0x000a) // Raspberry Pi Pico SDK CDC
 
-#define USBD_DESC_LEN (TUD_CONFIG_DESC_LEN + TUD_CDC_DESC_LEN)
+#define USBD_DESC_LEN (TUD_CONFIG_DESC_LEN + TUD_CDC_DESC_LEN * CFG_TUD_CDC)
 #define USBD_MAX_POWER_MA (250)
 
+enum
+{
+  ITF_NUM_CDC_0 = 0,
+  ITF_NUM_CDC_0_DATA,
+  ITF_NUM_CDC_1,
+  ITF_NUM_CDC_1_DATA,
+  ITF_NUM_TOTAL
+};
+
 #define USBD_ITF_CDC (0) // needs 2 interfaces
 #define USBD_ITF_MAX (2)
 
@@ -49,6 +58,12 @@
 #define USBD_STR_SERIAL (0x03)
 #define USBD_STR_CDC (0x04)
 
+#define EPNUM_CDC_0_NOTIF (0x81)
+#define EPNUM_CDC_0_DATA (0x02)
+
+#define EPNUM_CDC_1_NOTIF (0x84)
+#define EPNUM_CDC_1_DATA (0x05)
+
 // Note: descriptors returned from callbacks must exist long enough for transfer to complete
 
 static const tusb_desc_device_t usbd_desc_device = {
@@ -69,11 +84,14 @@ static const tusb_desc_device_t usbd_desc_device = {
 };
 
 static const uint8_t usbd_desc_cfg[USBD_DESC_LEN] = {
-    TUD_CONFIG_DESCRIPTOR(1, USBD_ITF_MAX, USBD_STR_0, USBD_DESC_LEN,
+    TUD_CONFIG_DESCRIPTOR(1, ITF_NUM_TOTAL, USBD_STR_0, USBD_DESC_LEN,
         TUSB_DESC_CONFIG_ATT_REMOTE_WAKEUP, USBD_MAX_POWER_MA),
 
-    TUD_CDC_DESCRIPTOR(USBD_ITF_CDC, USBD_STR_CDC, USBD_CDC_EP_CMD,
+    TUD_CDC_DESCRIPTOR(ITF_NUM_CDC_0, USBD_STR_CDC, EPNUM_CDC_0_NOTIF,
-        USBD_CDC_CMD_MAX_SIZE, USBD_CDC_EP_OUT, USBD_CDC_EP_IN, USBD_CDC_IN_OUT_MAX_SIZE),
+        USBD_CDC_CMD_MAX_SIZE, EPNUM_CDC_0_DATA, 0x80 | EPNUM_CDC_0_DATA, USBD_CDC_IN_OUT_MAX_SIZE),
+
+    TUD_CDC_DESCRIPTOR(ITF_NUM_CDC_1, USBD_STR_CDC, EPNUM_CDC_1_NOTIF,
+        USBD_CDC_CMD_MAX_SIZE, EPNUM_CDC_1_DATA, 0x80 | EPNUM_CDC_1_DATA, USBD_CDC_IN_OUT_MAX_SIZE),
 };
 
 static const char *const usbd_desc_str[] = {